In recent years, along with the ubiquitous mobile terminal devices such as portable telephone and PHS (Personal Handyphone System), there has appeared an information providing service for offering information such as advertisement to the mobile terminal devices. The requirement arising with such an information providing service involves an information offer using positional information on a person who possesses the mobile terminal device for accepting the information offer.
On the other hand, in the case of the mobile terminal devices such as portable telephone and PHS, there is a need to get hold of the present position of a mobile terminal device at all times for calling the mobile terminal device wherever the possessor of the portable terminal device is. Therefore, a mobile terminal device carrier such as portable telephone carrier or PHS carrier manages positional information on mobile terminal devices at all times while registering it in a position registering apparatus. That is, an area number indicative of a position registered area (paging area) is broadcased from a base station toward mobile terminal devices at all times, and a mobile terminal device periodically collates an area number stored in its storage unit with the currently broadcased area number to, in the case of no coincidence therebetween, make a request for the renewal of the position registration to the position registering apparatus, thereby managing the positional information on the mobile terminal device at all times.
In particular, in the case of the PHS, because one base station covers a small area, it is considered to offer an information providing service through the use of the positional information on PHS managed by a position registering apparatus. That is, whenever the positional information on the PHS is renewed in the position registering apparatus, the positional information is notified to an information sending server run by a third party other than the PHS carrier. On the other hand, it is considered that the information sending server makes a decision, on the basis of the positional information transmitted from the position registering apparatus, as to whether or not the PHS possessor enters a specific area, and sends the latest information (for example, advertisement, or the like) specializing in this area toward the PHS existing in the specific area, thereby realizing an information providing service through the use of the positional information on the PHS.
In addition, a portable telephone equipped with a GPS (Global Positioning System) function has recently appeared and, hence, an information providing service utilizing accurate positional information acquired through the GPS function is expectable in the future.
In this case, the following arrangement is conceivable.
That is, as shown in FIG. 10, each portable telephone 100 periodically measures a position thereof through the use of the GPS function, and transmits, in a constant cycle, the measured positional information through abase station 102 and an exchange 103, which constitute a mobile communication network 101, to a position registering apparatus 104 designed to manage the positional information on each portable telephone 100. Moreover, the positional information registering apparatus 104 is made to notify new positional information to an information sending server 105 run by a third party other than the portable telephone carrier whenever the renewal of the position registration is made on the basis of the positional information transmitted from each portable telephone 100. Moreover, on the basis of the positional information transmitted from the position registering apparatus 104 at every renewal of the position registration, the information sending server 105 makes a decision as to whether or not a person who carries the portable telephone 100 gets into a specific area, and transmits the latest information (for example, advertisement or the like) specialized in this area toward the portable telephone getting into the specific area.
Meanwhile, the positional information on a mobile terminal device is indicative of the location of the mobile terminal device possessor and is privacy information of the mobile terminal device possessor and, hence, this information requires extremely great protection.
For this reason, a mobile terminal device carrier such as a portable telephone carrier or PHS carrier is required to take a proper measure to protect the privacy of the mobile terminal device possessor when, for example, offering the positional information on the mobile terminal device to a third party. Moreover, this similarly applies to even a case in which a positional information provider other than the mobile terminal device carrier offers positional information on a mobile terminal device.
In addition, a third party which carries on an information sending server which receives the offer of the positional information on a mobile terminal device is also required to take a proper measure for the protection of the privacy of the mobile terminal device possessor.
However, in fact, a third party running an information sending server does not always take a proper measure, and it is uncaclulated to take a proper measure.
For example, in a case in which an information sending server run by a third party is not designed as a high-security system, there is a possibility that the positional information on a mobile terminal device leaks out, and difficulty is experienced in realizing the protection of privacy of a person (subscriber) who possesses a mobile terminal device.
In particular, in a case in which the positional information on a mobile terminal device is transmitted through the internet to an information sending server, there is another possibility of the positional information on the mobile terminal device leaking out on the internet.
Still additionally, even in a case in which a mobile terminal device possessor makes a registration for receiving the information offer using positional information thereon from an information sending server run by a third party, if the positional information on the mobile terminal device leaks from the information sending server and is used for purposes other than the information offer the mobile terminal device possessor intends originally, the protection of the privacy of the mobile terminal device possessor becomes unfeasible.
Yet additionally, as shown in FIG. 11, in a case in which an information sending server 105 run by a third party is made to acquire the positional information on a specified portable telephone (mobile terminal device) 100 from a position registering apparatus 104 at a constant cycle, the moving route of the possessor of the portable telephone 100 is made clear in the information sending server 105. In this case, if the moving route of the possessor of the portable telephone 100 leaks from the information sending server toward another server 106, there is a possibility of chase and abuse. Thus, the chase/abuse of the positional information on the portable telephone 100 can lead to the invasion of the privacy of the possessor of the portable telephone 100.